1. System Overview

The Benjamin System is a non-contact, zero-intrusion, self-powered MIDI capture architecture for top-tier acoustic grand pianos (e.g., bespoke Steinway). It delivers high-resolution digital performance data while preserving:

• Original action geometry
• Key and hammer inertia
• Regulation procedures
• Acoustic tone and resonance

There are no solenoids, no actuators, no under-key sensors, and no feel change. All sensing is case-mounted and non-contact. The system powers itself via vibration energy harvested from the rim, frame, and plate, waking only when the piano is played.

2. Sensor Architecture

2.1 Non-Contact Hammer-Flight Sensing

The core sensing uses Optical Hammer-Flight Capture (OHFC):

• Infrared emitters mounted under the stretcher lip (rim-side, not on the action)
• Photodiode or CMOS linear arrays mounted to the inner rim
• Sampling at ~1–2 kHz per hammer arc

These sensors read the full hammer trajectory in free flight: position, velocity, and acceleration, including subtle pre-let-off, aftertouch characteristics, and release profiles — all without touching any moving part.

2.2 Optional Magnetic Enhancement

An optional, ultra-light enhancement uses Hall-effect magnetic tracking:

• Sub-milligram magnetized lacquer micro-dots on hammer shanks (≤ 0.05 g variance)
• Hall-effect sensors mounted in the rim read the hammer arc
• Full 3D motion reconstruction for research-grade analysis

This remains below natural manufacturing variability in hammer felt and does not alter touch.

3. Energy Harvesting Architecture

The system is self-powered solely by playing. No external power is required. Energy is harvested from the instrument’s own vibration, without loading the action.

3.1 Acoustic Energy Harvesters (AEH)

AEH units are rim-mounted piezoelectric or triboelectric films that capture vibration energy:

• Mounted on the inner rim, not on the soundboard
• Typical output: ~5–40 mW (dynamic, depending on playing level)
• No impact on tone, since the soundboard and plate remain untouched

3.2 Inertial Frame Harvesters (IFH)

IFH units are isolated micro-inertial devices attached to the frame/case:

• Internal inertial mass oscillates relative to frame vibration
• Generates 1–10 mW during active playing
• Mechanically isolated so no mass is added to action components

3.3 Plate Resonance Harvesters (PRH)

PRH units are non-contact electromagnetic flux harvesters near plate ribs:

• Small coils placed a few millimeters from plate structures
• Capture EM changes induced by the vibrating metallic plate
• Generate an additional 1–15 mW

Combined, AEH + IFH + PRH easily provide the 5–10 mW needed for continuous sensing and MIDI transmission.

4. Electronics & Power Regulation

4.1 Storage & Regulation

• UltraCapacitor (10–50 F) as energy buffer and “heart” of the system
• Low-noise LDO regulators produce isolated 3.3V and 5V rails
• No batteries; no chemical aging; effectively infinite recharge cycles

4.2 MIDI Controller

A low-power microcontroller (e.g., STM32 or ESP32-S3 class) handles:

• ADC sampling of sensor lines at 1–2 kHz
• Hammer-flight trajectory reconstruction (DSP)
• MIDI encoding: BLE-MIDI, USB-MIDI, and/or 5-pin DIN
• Ultra-low-power sleep between notes and between sessions

The system wakes the moment the piano vibrates and sleeps in silence, like a living organism.

5. Compliance & Manufacturing Requirements

To guarantee that the piano remains a pure acoustic concert instrument with added witness capability, the following constraints are mandatory:

• No component may contact, load, or alter any part of the action (keys, wippens, jacks, repetition, hammers, shanks, knuckles).
• No change to key weight, leverage ratios, dip, or aftertouch is permitted.
• No drilling, cutting, or modification of the soundboard or plate.
• All sensing hardware must be rim-mounted, stretcher-mounted, or within existing non-structural cavities.
• Hammer mass change (if micro-dots are used) must remain ≤ 0.05 g per hammer.
• Action removal and regulation procedures must remain identical to the non-MIDI version of the same model.
• No actuators or solenoids may be installed; the system is MIDI capture only, not a player system.

6. Music Industry Impact — Overview

The Benjamin System introduces a new class of instrument to the music world: a pure acoustic concert grand that can:

• Witness itself digitally
• Capture high-resolution performance data
• Operate without external power
• Retain completely uncompromised touch and tone

This creates a fourth category of piano technology:

• Acoustic
• Digital
• Hybrid (player systems like Disklavier/Spirio)
• Acoustic-Digital Witness (“Benjamin Class”) — new

7. Impact on Steinway & High-End Piano Makers

7.1 Spirio and Similar Systems Become Legacy Tech

Current systems (e.g., Spirio, Disklavier) are:

• Action-intrusive (solenoids, under-key sensors)
• Heavier and more complex mechanically
• Dependent on external power and subscription content
• Not purely neutral with respect to touch

The Benjamin System demonstrates that a non-intrusive, self-powered approach is possible and superior. This renders existing player systems technologically and conceptually outdated for high-fidelity performance capture.

7.2 A Flagship, Non-Reproducible Bespoke Instrument

A bespoke Steinway built to this specification becomes:

• A one-of-one reference instrument
• A technological and artistic flagship
• A potential blueprint for future lines (e.g., “Steinway Benjamin Edition”)

If Steinway adopts the architecture, it reshapes their entire long-term product roadmap. If they decline, the instrument remains a uniquely valuable, historically significant outlier.

7.3 Licensing & Strategic Partnerships

Piano makers and related tech firms (Yamaha, Kawai, Fazioli, Bösendorfer, etc.) may seek:

• Licensing of the Benjamin System architecture
• Collaboration on flagship models
• Reference instruments for sampling and modeling

8. Impact on Artists, Recording & Pedagogy

8.1 True Performance Capture Without Compromise

For the first time, pianists can have:

• Uncompromised acoustic performance and full-fidelity digital capture
• No feel difference compared to a non-MIDI concert grand
• Immediate availability of audio plus high-density MIDI and motion data

This is highly relevant to concert artists, film/game composers, and serious recording projects.

8.2 New Modes of Analysis & Pedagogy

The captured data can be used to:

• Analyze touch, timing, dynamics, and pedaling at micro-resolution
• Train AI models of individual performers
• Provide visual feedback for students and masterclasses
• Compare interpretive fingerprints across artists

8.3 New Performance Formats

Concerts using such an instrument can:

• Project live visualizations of hammer arcs and dynamics
• Stream both audio and MIDI for real-time re-rendering on other instruments
• Archive performances in both sound and structured performance data form

9. Technological, Market & Cultural Impact

9.1 Reference Architecture for Future Instruments

The Benjamin System introduces a new reference model for instrument design: self-powered acoustic instruments that witness themselves digitally without altering their identity.

This influences:

• Future piano designs
• Other acoustic instruments (strings, winds, percussion) with non-intrusive capture
• Standards for what “high-fidelity digital capture” means in music

9.2 Economic & Collectible Value

A bespoke Steinway implementing this architecture is:

• Comparable to first-generation Stradivarius violins or landmark synthesizers (e.g., original Moog modular)
• Likely to appreciate in value due to uniqueness and technological significance
• A magnet for recording studios, labels, and high-end session work

9.3 Cultural Shift Toward Authenticity & Data-Rich Creativity

By uniting uncompromised acoustic sound with detailed performance data, this system:

• Supports more authentic, less synthetic musical experiences
• Enables deep creative recombination via MIDI and sound modeling
• Establishes a new norm where major performances are both heard and structurally recorded